Self aligning electrolysis cell



June 14, 1960 J. D. MUELLER ET AL 2,940,918

SELF ALIGNING ELECTROLYSIS CELL Filed July 7, 1958 s sheets-sheet 1 FIGURE June 14., 1960 J. D. MUELLER ETAL 2,940,918

SELF ALIGNING ELECTROLYSIS CELL Filed July 7, 1958 3 Sheets-Sheet 2 FIGURE 2 3 Sheets-Sheet 3 11 I? K I I I I F I 1 M I;

J. D. MUELLER ET AL SELF ALIGNING ELECTROLYSIS CELL June 14, 1960 FIGURE 3 Filed July 7, 1958 Fl GU RE 4 United States Patent SELF ALIGNING ELECTROLYSIS CELL John D. Mueller, Baton Rouge, La., and Ernest C. Singletary, Dallas, Tex., assignors to Ethyl Corporation, New York, N .Y., a corporation of Delaware Filed July 7, 1958, Ser. No. 746,773

6 Claims. (Cl. 204-243) This invention relates to improvements in fused salt electrolysis cells. More particularly, the invention relates to improved support structures for preserving a specific registration and alignment of a plurality of elements in such cells.

Various light metals, in particular the alkali metals, especially sodium, are produced by the electrolysis of fused baths or electrolytes of the halide compounds of the desired metals. For example, in the production of sodium, a fused bath containing a predominant proportion of sodium chloride, and lesser proportions of calcium chloride, is electrolyzed at a relatively elevated temperature, of the order of about 500-700" C. to release the elemental sodium metal. This operation has long been carried out in cells generically of the type originally disclosed by Downs in US. Patent 1,501,756. The Downs cell utilized a bottom mounted graphite anode and a cathode assembly having a cylindrical cathode generally concentric with and surrounding a substantial portion of the cylindrical anode stick. By bottom mounted anode is meant that the anode rests on the bottom of the cell shell or enclosure and that electricity is conducted to the anode by a connection through the bottom. The electricity was conducted to the cathode by connection to bus bars by means of lugs or arms projecting from the cylindrical portion of the cathode assembly, or cathode proper, through the walls of the cell to external bus bars for bolted connections.

For many years cells of this type utilized single anodes, and of course single cathode cylinders around the anode in their construction. This design was quite operable and relatively satisfactory, but was limited in capacity, that is, resulted in installations which were limited in production capacity for a given amount of factory space. In recent years a new type of cell has been provided which uses a plurality, usually four, of anodes. In this improved cell, the cathode assembly includes a number of cylindrical portions joined together and adapted to surround each of the anodes generally in the same fashion as in the original Downs cell. Cathode arms project from the assembly through the cell walls and make connections to external bus bars. In plural electrode cells of this type, as in the original single anode cell, foraminous, cylindrical metal diaphragms are provided. One such diaphragm is positioned around each anode, and within the corresponding cathode space. It is seen, then, that the diaphragm cylinders divide the annular space between each anode and corresponding cathode, into two concentric annular zones.

The shells of sodium cells include a steel jacket or shell proper, and a lining of refractory brick or cast refractory material. The cathode arms pass through openings in this composite wall, and are sealed for retention of the electrolyte by suitable poured refractory or other sealant material surrounding the cathode arm and filling the opening in the cell wall. A collector providesan outlet port for removal of the gaseous chlorine and also con- 2,940,918 Patented June 14, 196.0

ice

tains an annular inverted channel for manifolding and removal of the metallic sodium. The collector is sup ported by a frame which in turn is attached to and is supported by the cell walls. The diaphragms are hung from the collector.

It is well known that the precise alignment of the oathode cylindrical portions and diaphragm assemblies, with respect to the anode sticks, and with respect to each other, is essential for most effective operation. By precise alignment of these members is meant not only that the lateral displacement of the centers of the cathode portions and the diaphragm assemblies with respect to the centers of anode sticks must be maintained, but also the vertical alignment. Stated another way, this means that the central axis of the cathode portions and the diaphragm assemblies should coincide with the central axis of the anode which it surrounds. Thus, each of the cat ode portions and diaphragm assemblies is originally centrally aligned and concentric with each of the anodes which it surrounds. Each of the diaphragm assemblies is located substantially midway between the anode and cathode members. A structure for providing the desired alignment of the anodes is that shown in the Carlisle US. Patent 2,648,651, wherein a mounting and clamping for precise initial orientation of an anode is disclosed.

Heretofore, the cathode assembly generally described above was initially aligned quite precisely and its position Was maintained only by its initial placement. Maintenance was assumed because of the fact that, because of its large weight, displacement was not expected to occur. This assumption was early recognized as erroneous but was not significantly serious in the early operations of single anode cells. However, since the advent of multiple anode cathode cells, any displacement of the cathode assembly occurring during extended operation of such cells has resulted in serious drawbacks.

It will be understood that any major change in lateral displacement of a cathode with respect to the fixed alignment of the anode sticks is accompanied by a change in the spacing or dimensions of the electrolysis zones, these zones being the rather lengthy annular spaces defined by the anode cylinder sticks and the surrounding cathodes. In operation, unfortunately, the high temperatures of operation result in appreciable warping of the steel cell shells. Since heretofore the cathodes have freely rested upon the cell shells by means of the arms already described, appreciable warping, or uneven warping on the several sides of the cell has resulted in appreciable skewing or displacement of the cathode laterally, or even in a rotation of the cathode assembly about a vertical axis of the cell.

A major and specific need accordingly has existed for a cell structure wherein the lateral displacement, or the circumferential displacement of the cathode assembly was more or less permanently established. it was thought that rigid mounting of the cathode externally of thecell would achieve the desired permanent registration, until it was realized that the quite large temperature changes occurring in starting up operations and during operation of the cell for an extended period would impose very large strains upon the metal of the cathode assembly if the external mountings were strong enough to resist the forces of expansion. Hence, this rigid mounting technique would not be satisfactory.

Heretofore also, the collector, to which is afiixed the diaphragms, was freely rested upon the cell walls by means of arms attached thereto. Warpage of these walls produced displacement of the diaphragms from their norcathodes which was very undesirable since this formed :of a cell and to resist conducting paths of lower resistance than across the 7 electrolyte; This often caused the actual deposition of metallic calcium .and impurities within the electrolysis zones between the anodes andcathodes. This effect has 7 been termed calcium bridging. Calcium bridging between the cathodes and the diaphragms often actually produced a current flow the diaphragms themselves, sometimes resulting in burningholes in the diaphragms. Recombination of the elements separated by the electrolysis .also resulted. These phenomena are manifested by a marked decrease in the current efiiciency of the cell and in the total time of useful service of the diaphragms. To replace the diaphragms a major portion of the cell must be dismantled. This, of course, is inherently expensive, largely because the productive capacity of the plant is reduced.

From the foregoing it is fully realized that the concentricity and vertical orientation of the surrounding diaphragms and cathode portions with respect to the anodes is an important attribute of an operating cell. Attaining this objective has been along standing problem in the industry. The difliculty of maintaining this alignment can be appreciated when it is realized that the normal V the order of about l' /z inches and for best operation the diaphragm must be maintained equidistant from the anode and cathode. These-distances 'must be maintained over 'the'entire length of the anode, which is. usually from two to five feet. changes at the ,cell wallson the'members which support the cathode portions and diaphragms produce dimensional changes which greatly affect the interrelationship of the 7 said members and therefore proper operation of the cell.

i 3 It is accordingly an object of the present invention to provide a new and improved fused salt electrolysis cell. More. particularly, an object of the present invention is to provide new and novel support and registration struc- Obviously then, minute dimensional lateral distance between an anode and a cathode is on ture for preserving the central alignment of individual annular elements surrounding the anodes which are susceptible'ito displacement as a result of thermally induced dimensional changes. An object of a specific form of the present invention is to provide structure suitable for said 'cell.

three in number, have bottom guides in a horizontal plane,

tached; In embodiments, this portion may itself form the elements to individually surround the individual anodes. Extended from this portion are projections which project beyond the normal confines of the shell of the cell. These projections, being at least three in number, each include bottom guides in a horizontal plane, guide blocks for the bottom guides, and cooperating guide block supports associated with each. of the said bottom guides and guide blocks. The guide block supports are adapted to permit relative movement of the bottom guides only in a direction radial to the center of the cell, whereby the central alignment of the said assembly of elements surrounding the anodes is generally preserved with respect to the anode disposition, despite thermally induced dimensional changes.

One species of the invention provides an improved cathode assembly and support means which includes a cathode structure with a vpluralityof arms projecting through the walls of the cell. These arms, being at least three in number, are generally approximately uniformly 'circumferentially spaced in a horizontal plane, and have center lines which project approximately through the center of the cathode assembly. The arms are adapted to support the cathode assembly and havebottom guides in a horizontal plane for engaging in sliding contact with cooperating guide blocks and guide block supports. These aflixed to and form a portion of a cell base. I 30 Another species of the invention provides an improved diaphragm supporting assemblywhich includes a rigid supporting structure for the diaphragms and has supporting legs which extend beyond thenormal confines of the Each of the supporting legs, being at least guide blocks for the bottom guides, and guide block supports associated with each of the said bottom guides and guide blocks. The guide block supports are adapted to permit sliding contact or movement of the bottom guides preserving the desired orientation of the cathode portions the'effect of thermally induced dimensional changes. An additional object of another form of the present invention is to provide a structure for performing a similar support and position retaining influence for a collector and diaphragm assembly. A particular object of .a highly efiective and preferred embodimentis to provide a cell with support and position retaining structures which serve to preserve the proper registration and alignment of both the cathode assembly and the diaphragms of a multi-electrode cell of the type described.

The details of construction of the. apparatus of the invention will be morefully understood from the description hereinafter and fi-om the figures illustrating particular embodiments, wherein Fig; 'l is anisometric view of a cell assembly showing application of a specially preferred embodiment of the invention providing for support and maintenance of positions of both the cathode structure and a of the diaphragm assembly. Fig. 2 is a horizontal sec-. tional view along line.1--1 of Fig. 3 of .the improved cathode structure and mounting means, and Fig. 3 is an elevation view of the same apparatus. Fig. 4 is a vertical section detail taken along lines 3-3 of Figs. 2 and 3 showing a portion ofa typical mounting means. a

; The invention-is generally outlined below, with particu- "lar reference to twoembodiments.

Broadly,.the invention'provides mproved support and alignment means or structure'for preserving the central alignment of the individual elements surrounding the anodes in fused salt electrolysis cells such as the Downs Thesupport and alignment means includes a comonly ina direction radial to the center of the cell. This preserves the central alignment of the surrounding. diaphragm assemblies with respect to the anodes during thering structure or, desirably can be affixed to and form a portion of the arms of the cathode assembly as described more specifically hereafter.

A particular preferred embodiment of the invention provides support and alignment structures for both the cathode assembly and for the diaphragms, and further,

provides for vertical co-action of these structures.

The'principle of the invention and the several embodiments thereof will be fully understood from the following detailed description.

Fig. 1 is an isomeric view of a self aligning cell in operative position, with a section of the cell wall cut away, and other minor sections also cut away, or omitted, to show a highly preferred embodiment of the support and alignment structure of the. invention applied to both the cathode and diaphragm supporting structure. The wall of the cell is generally, of square outline, with rounded corners. The, cell wallincludes an exterior cell shell of steel plate 7,'-and lining of refractory material 8. The plan disposition of the cell elements is more readily seen in Fig. 2, which shows a horizontal section 3 A cathode assembly 15 includes four generally cylindrical portions 16 16 16 16 surrounding the individual anodes 9 and forming therewith annular electrolysis zones 171, 17 17 17 into which the diaphragms 53,, 53,, 53,, 53, are extended. The cylindrical portions 1 6 163, 16 16 of the cathode assembly are joined together by welding or by tangential connections of the walls thereof, and by webs connecting several of the cylindrical portions 16. Electrode or conductor arms .26 25 for current carrying pruposes extend from the cathode assembly and projects through the openings 39;, 30 of the cell Wall. The said openings are filled with a castable refractory material 31 31 Extending from the described assembly of cylindrical cathode portions 16, or cathodes proper, are a plurality of support arms 19 19 19 19 At least three such support arms are required. Each of the support arms 19 extends through an opening 21 21 21 21 in the cell Wall, and terminates, outside the cell wall, in a downwardly projecting shank 69 69 69 (Fig. l) which rests upon the cell base 25 or upon cell base extensions 12 12 12 provided therefor. In the construction .of the cell the aperture between the support arm cross section and the opening is filled with a castable refractory material 22 22 22 22 The arms 19,, 19 19 19 are generally rectangular in cross section at the point of passing through the cell wall, and are of sufliciently large proportion to easily support the relatively large weight of the cathode assembly 15. The arms 19 are disposed in angular relation to each other and project radially outwardly in a plane which if extended would intersect, or approximately intersect, at a point which is the center of the cathode assembly, and which by construction of the cell coincides with the center of the cell. It will be seen that support of the cathode by slideable support of the support arms 19 (by slideable meaning that movement of an arm 19 to or from the center of the assembly is permitted, but not circumferential displacement on an are having the cell center as its center) will not result in displacement of the cathode center from its original disposition. In other words, thermal expansion of the cathode assembly 15 would be manifested in corresponding movement of the arms 19 radially, or outwardly, away from the center. As all support arms 19 would so move, and movement only in a direction radially from the center is permitted, it will be seen that the normal orientation of the cathode assembly with respect to the anodes is not disturbed.

Referring to Fig. 1, outside and straddling the cell proper is also shown a table or rigid support frame 41. The vertical portion thereof is always comprised of a plurality of not less than three legs. In this embodiment four legs 42 42 42 are provided, each resting upon the top of a cathode support arm 19 19 19 In all embodiments of the invention it is necessary that the diaphragms be electrically insulated from the anodes and cathodes (except as circuits are established Within the cell). A suitable mode of providing such external insulation is described hereinafter. The key feature of the support frames is that there is provided a restricted or unidirectional sliding contact between the terminus of each of the legs 42 42 42 and the top of a mating cathode support arm. Thus, when a cathode arm 19 19 19 moves outward in a direction away from the center of the cell, the terminus of the corresponding support leg 42;, 42 42,; remains in a relatively fixed position and the cathode arms slide relative thereto. Alternatively the support leg may slide in similar fashion with respect to the cathods arm 19.

The horizontal portion of the support frame 41 is composed of two rigid parallel members or I beams 45 45 each of which joins together a pair of the four said legs 42;, 42 42 42 Resting upon and parallel with the said members 45 45 are 2 bars 44 44 A collector support frame 47, is composed of four lengths of metal and which forms an open rectangle which can be electrically insulated, from the 2 bars 44 44 by the insulator blocks 46 46 46 The collector 43, to which the diaphragms 53" are aifixed, is rigidly secured, by means of vertical connecting bars 80 80 to the collector support frame 47 and is entirely dependent upon it for support. The support frame assembly 41 .thus positioned is, like the cathode assembly 15, substantially independent of the movements of the cell proper caused by thermal expansion.

If desired, one .or more of the support arms 19 can further serve as a current carrying means. Whether the support arms 1-9 are used as electrodes or not, however, it is required that each of these members be electrically insulated from the cell wall and cell base 25. This can be done in a number of ways. One preferrd method is to provide ceramic insulators in the form of guide blocks for using a .part of the support and alignment means. Use of the support arms 19 as electrodes is, .of course, not an essential feature of the invention, but can be utilized to avoid the necessity of an additional arm, or arms, if it is desired.

The shanks or extension legs 27 which project downwardly from the support arms 19 are either integrally formed with the support arms 19, or are extensions securely "fastened thereto by welding or other positive fastening means. These extension legs bear on, in sliding contact as described in more detail later, the cell base extensions 12 previously mentioned, and support the full weight of the cathode assembly 15. In addition, in the preferred embodiment, these extension legs or shanks 27 support the full weight of the support frame assembly 41 which rests thereon (including the constituent members which it in turn supports as already mentioned). The legs 42 of the support frame 41 bear on (also by sliding contact as will be fully described later) the upper Portion of the shanks 27.

Turning again to Fig. 2, plan view of a section along the lines 11 of Fig. 3 shown, illustrating particularly the improved cathode mounting assembly 15. Centrally arranged, within the confines of the cell wall are four cylindrical graphite anodes 9 9 9 9 A cathode assembly 15 includes four generally cylindrical portions 16 16 16 16 surrounding the individual anodes ,9 and forming therewith annular electrolysis zones 17 17 17 17 Extending from the cathode assembly 15 are four support arms, 19 19 19 19 and two supplemental conductor arms 26 26 Each of the support arms 19 extends through an opening 21 21 21 21. in the cell wall to the exterior of the cell. Similarly, the conductor arms 26 extend through the openings 30;, 3& to the cell exterior. It is necessary for the purposes of the invention, that the cathode assembly 15 be relatively uninfluenced in position by the precise position of the cell walls. In other words the joint between any cathode arm 19, or electrode 26, and the cell walls through which the said arm 19, or electrode 26, is ex tended shall be a sliding fit. Thus, the openings 21 within the cell wall, through which the support arms 19 are extended are filled or packed with a refractory or sealant material 22 22 23 23 Also, the openings 30 through which the conductor arms 26 are extended are filled with a similar material 31 31 The hydraulic sealing function of this material is important, but it is not absolutely essential that a liquid tight fit be provided. In practice it has been found that the high melting electrolyte contained within the cell proper tends to solidify adjacent the walls or at any point at which sufficient heat transmission to the external atmosphere is provided to allow solidification, and this occurrence results in a self sealing condition. It is clear that support of the cathode 15 by slideable support of the support arms 19 will not result in displacement of the cathode center from its original disposition. Thus, thermal expansion of the cathode assembly 15 will be mainfested in corresponding movement of the arms 19 away from the center and the relative position of the anodes 9 therewith will be unaltered.

The mode of functioning of the cathode support arms 19 in maintaining the desired orientation of the cathode assembly 1-5 with respect to the anode 9, is illustrated more fully by Fig. 3, which is an elevation view of the cathode assembly of Fig. 2, and the cell base associated ither'ewithI. Turning to Fig. sit-Twill be seen that the major portions of the assembly includeac'e'll base 25,

theanodes '9, and thecathode. assembly 15. The cell base 25 is a cast or fabricated steel structure corresponding generally in outline to the external dimensions of the cell shell 7 At four points projecting from the periphery of the cell base 25 are'bas'e extension plates 12 12 (12 12 Fig. '2), these being'further supported by reinforcing angle brackets 13 134 (13 13 not shown). The anodes 9 project upwardly as far as the upper surface or extremity 2310f the cathode assembly 15. The anodes 9 are securely mounted in a laterally registered and vertically aligned position, by the base 25 by various known As already mentioned the four cathode supportarms 19 are provided extending radially in planes which, if projected, would approximately intersect at-the center of the cathode assembly 15. I 1

Projecting downwardly-from the cathode support arms 1 9 19 are the shanks or extension legs 27 27 These extension legs 27 bear on and are in sliding contactwith the cell base extensions 12 ,12 12 12 and support the full weight of the cathode assembly 15. The legs 42 42 42 42 ofthe support 'frame 41 also hear on and are in sliding contact withjthe upperportion of the cathode armsf19 19 19 19 unique arrangement permits full support of'all the components of the cell and yet fully maintains the proper orientation or central alignment of the cathode portions and diaphragms with respect to the anodes during thermal expansions or contractions of the cell. 1

' Preferred guide" means are shown, in Fig. 4, for restricting movement ofthe support structure-portions, to movement in a radial directionfrom' the center .of the cell. Fig; 4 is a vertical section '3-3 of an extension leg 27;, and a support leg 42 A guide plate 28 is fastened to the cell base extension 12;by bolts 29. The

guide plate 28-, is provided, with a shallowgroove or guide block support 33, machinedtherein. The guide block support 33 is generally centered on'a horizontal. plane intersecting the center of the cell,'or more properly,

.of-the cathode assembly 15. Positioned in the guide block support 33 is a support element or guide block 34 This guide block 34 is, suitably'of a ceramic'electricallyinsulating material and is precisely fabricated to snugly fit or rest in the guide way or guide block support 33 with only a minimum amount of side play, for example with a clearance of about.0.01 to 0.02 inch. This clearsponding'movement from the. other member. The'sum totaleifect is that these members adiustjthemselves during thermal changes and yet maintain the centralalignment of the diaphragms 53 and cathode portions 16 with respect to the anodes. 9; i

It will be apparent that the details of construction of the several embodiments of the invention can be widely varied-without materially departing from the principles illustrated by the above embodiments. For example, instead of 'a ceramic support bar or guide block of square or rectangular cross section as described above, various other materials or other cross sections would be quite adequate providing that they are susceptible of assuring the restn'cting sliding contact already discussed in supporting the cathode assembly on the base extension plates; For example, the guide blocks need not be separate, but instead the assembly can provide a spline or a tongue. and

groove arrangement. Also, guide blocks of triangular or round cross section would be quite suitable. The rectangular or square cross sectional guide bar, however, does have an advantage. With such guide bars, alignment is attained by the vertical side walls of the bottom guides and guide block'supports in the ends of the support arms 'on the guide plate. If oval, triangular or. diamond shape guide blocks are used, reliance must be placedon the weight of the cathode assembly to provide horizontalforce vectors. On the other hand the square or rectangular cross sections produce vertical side walls which place no reliance on the weight of the support frame or cathode assemblyto provide such horizontal forces. Likewise,

though a ceramicinsulating material is preferred many materials of construction may obviously be employed;

ancejpermits quiteprecise alignment of the guide block 34 in the aforementioned plane. Resting on the guide block 34 is the terminal end of the extension leg 27 of the cathode arm 27 which has machined in the lower extremity thereof the bottom guide 35 This bottom guide 35 is of the same dimensions as the support face or guide block support 33 in the guide plate 28 'Machined in the upper extremity of the cathode support arm 19 is a guide block support 73 into which fits another precisely fabricated guide block or ceramic bar 74 The guide block support 73 is, preferably, similar :in dimensions to the guide block support 33 A bottom guide 75 which is similar in dimensions to the guide block support 73 is also machined in the lower extremity of the supportframe leg 42 V 4 Corresponding support and .alignment'assemblies are positioned on the three other extension legs 27 27 27 and support arms 19 19 19 a The effect of these support and alignment mechanisms described is, then, to create a tongue and groove arrangement'between the cathode arms 19 and'the cell base extensions 12, and between the support frame assembly 41 and the. cathode arms 19, such that any movement of these members produced by thermal stresses is in a radial 7 direction from the center of the cell; "It is also clear that the support frame ,41 and the cathode assembly 15 canadjust themselves independentlyor without corre- Generally this invention is directed to cellsv wherein a generally symmetrical. arrangement of electrodes is .provided; By this is meant. that-cells having an extremely long length to width plan configuration would not be particularly susceptible to this device. The invention is however peculiarly applicable to any cell having either a single anode cathode combination, or having a plurality of anode cathode combinations arranged in a generally symmetrical pattern, i.e. three anodes on an equilateral triangular 'pl'an,,four anodes'on a square plan or six anodeson a regular hexagonal plan. This type of cell plan configuration is, of course, particularly susceptible of preservation of uniform electrolysis zone "dimensions by the maintenance of registration of a central axis as in the embodi ments above described. T

The applicability of the improved cathode support structure is not limited tocells operating with fused salt electrolytes, but the problem of thermal expansion as a vIn addition the. extreme. temperature ranges encountered by such cells tend to-warp the .cell wall shells'aspreviously mentioned. In past practices when cathode assemblies and collector and diaphragm assemblies were. sus

pended or supported by the cell-wall proper, uneven buckling or warping of the opposite sides of. a cell wall resulted in uncontrollable displacement of the cathode-diaphragms or other subassemblies. which should be preserved in constant relation to the anodes. In other words,

since the cathode structure for example. was supported by the cathode arms projecting through the walls, and the walls usually warped unevenly, thetendencywas to drag the cathode assembly along. The wall; repositioning was' not uniform in the several spots, hence there was exhibited a lateral displacement of the entire cathode structure. 7

This application is a continuation in part of our application, Serial Number 63l,089, filed December 28, 1956, now abandoned.

Having fully described the invention what is claimed is:

1. In a fused salt electrolysis cell having a plurality of vertically aligned anodes mounted at the bottom of said cell, and having further individual elements concentric with and surrounding each of said anodes, said elements' being susceptible to displacement due to thermally induced stresses produced during operation of said cell, an improved support and aligning system for the said elements comprising a common support member therefor, the elements being attached to said support member, said support member having projections extending beyond the normal confines of said cell, said projections being at least three in number and including bottom guides in a horizontal plane, guide supports for engagement of said bottom guides, and means associated with the bottom guides and guide supports, said means being adapted to permit relative movement of the bottom guides only in a direction radial to the center of the cell, whereby thermal induced dimensional changes result in substantial maintenance of the lateral orientation of said elements.

2. The apparatus of claim 1 further defined in that the bottom guides include a downward opening groove, extending radially from the center of a cell, and the guide supports include a matching, upward opening groove, and the means associated with said guides and guide supports are guide blocks of electrically insulating material slidably positioned in said grooves.

3. In a fused salt electrolysis cell having a multiple electrode system including a plurality of horizontally spaced vertically aligned anodes and a cathode member including individual portions surrounding each of said anodes, the improved cathode supporting and aligning system in which the cathode member has at least three integral mounting legs projecting horizontally outwardly through the cell wall at approximately equally spaced radial angles around a point at the center of the cathode member, said legs having mounting supports that are self-adjusting with respect to radial movement of the legs but which are restrictive of leg movement circumferentially with respect to the cathode center, whereby thermally induced dimensional changes of the cathode member result in substantial maintenance of its horizontal orientation to the anodes.

4. In a fused salt electrolysis cell having a multiple electrode system including vertically aligned, bottom mounted anodes and a cathode member including individual portions surrounding each of said anodes, the improved cathode supporting and aligning system including at least three mounting legs associated with the cathode, said legs projecting from the cathode proper through the cell wall and being distributed in a horizontal plane at approximately equal angles around a point at the center of the cathode member, and having bottom guides adapted to engage guide blocks as hereafter defined, and guide block supports for the mounting legs, the supports being at approximately equal angles around a point at the center of the anode plan in a horizontal plane, and guide blocks of insulating material mounted on said supports, said blocks being aligned approximately radially from the cell center and engaging the bottom guides of the cathode support legs, whereby thermally induced dimensional changes of the cathode result in substantial maintenance of its lateral orientation to :the anodes.

5. In a fused salt electrolysis cell having a plurality of vertically aligned cylindrical anodes mounted at the bottom of said cell, and having further a diaphragm assembly including diaphragms concentric with and surrounding each of said anodes, said assembly being sus ceptible to displacement due to thermally induced stresses produced during operation of said cell, the improved means of providing support and alignment of the said diaphragm assembly comprising a collector and diaphragm support and alignment structure, said structure consisting of a rigid support frame including a rec tangular portion located on a generally horizontal plane and having a plurality of supporting legs perpendicularly attached thereto, said rigid support frame being at tached to and supporting the collector to which is attached diaphragms, and providing further that the rigid supporting structure has .at least three supporting legs positioned beyond the normal confines of the said cell, said supporting legs including bottom guides in a horizontal plane; and guide blocks for the bottom guides, and guide block supports associated with each of said bottom guides and guide blocks, said guide block supports being adapted to permit relative movement of the bottom guides only in a direction radial to the center of the cell, whereby thermally induced dimensional changes result in substantial maintenance of lateral orientation of the diaphragms.

6. In a fused salt electrolysis cell having a plurality of vertically aligned cylindrical anodes mounted at the bottom of said cell, and having further a cathode assembly including individual cathode portions and a diaphragm assembly including individual diaphragms, the said cathode portions and diaphragms being substantially concentric with and surrounding each of said anodes, said diaphragms being located substantially midway between the individual cathode portions and the anodes,

an improved support and aligning system including a cathode supporting and aligning system, and a collector and diaphragm support and alignment structure, coacting with the cathode supporting system as defined hereinafter, said cathode supporting and aligning system ineluding at least three mounting arms associated with the cathode, said arms projecting from the cathode proper through the cell wall and being distributed in a horizontal plane at approximately equal angles around a point at the center of the cathode member, the collector and diaphragm support and alignment structure including a structure consisting of a rigid support frame including a rectangular portion located in a generally horizontal plane attached to and supporting the collector to which is attached the diaphragms and providing further that the rigid supporting structure has a plurality of legs equal to the number of cathode mounting ar-ms, said legs being positioned outside the normal confines of the cell, each of said legs resting upon and being supported by the cathode mounting anms, said collector and diaphragm supporting legs and cathode mounting arms having bottom guides in a horizontal plane, guide blocks for the bottom guides and guide block supports associated with each of said bottom guides and guide blocks, the guide block supports associated with the bottom guide and guide blocks of the collector and diaphragm supporting legs being located on the upper surface of the cathode support arms and the guide block supports of the cathode support arms being located upon the cell base whereby thermally induced dimensional changes result in substantial maintenance of the lateral orientation of the cathode and the diaphragms.

No references cited. 

1. IN A FUSED SALT ELECTROLYSIS CEL HAVING A PLURALITY OF VERTICALLY ALIGNED ANODES MOUNTED AT THE BOTTOM OF SAID CELL, AND HAVING FURTHER INDIVIDUAL ELEMENTS CONCENTRIC WITH AND SURROUNDING EACH OF SAID ANODES, SAID ELEMENTS BEING SUSCEPTIBLE TO DISPLACEMENT DUE TO THERMALLY INDUCED STRESSES PRODUCED DURING OPERATION OF SAID CELL, IN IMPROVED SUPPORT AND ALIGNING SYSTEM FOR THE SAID ELEMENTS COMPRISING A COMMON SUPPORT MEMBER THEREFOR, THE ELEMENTS BEING ATTACHED TO SAID SUPPORT MEMBER THEREFOR, SUPPORT MEMBER HAVING PROJECTIONS EXTENDING BEYOND THE NORMAL CONFINES OF SAID CELL, SAID PROJECTIONS BEING AT LEAST THREE IN NUMBER AND INCLUDING BOTTOM GUIDES IN A HORIZONTAL PLANE, GUIDE SUPPORTS FOR ENGAGEMENT OF SAID BOTTOM GUIDES, AND MEANS ASSOCIATED WITH THE BOTTOM GUIDES AND GUIDE SUPPORTS, SAID MEANS BEING ADAPTED TO PERMIT RELATIVE MOVEMENT TO THE BOTTOM GUIDES ONLY IN A DIRECTION RADIAL TO THE CENTER OF THE CELL, WHEREBY THERMAL INDUCED DIMENSIONAL CHANGES RESULT IN SUBSTANTIAL MAINTENANCE OF THE LATERAL ORIENTATION OF SAID ELEMENTS. 